JP2012198372A - Drawing device and drawing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drawing device and a drawing method for stably performing overlapped drawings without complicating the design of an optical system.SOLUTION: A drawing device includes an image pickup part 50 and a light-irradiation part 40, and performs: calculating a positional shift amount of a lower pattern caused by the deformation of a substrate on the basis of a pick-up image and the movement error of a stage 10 during the pick-up; detecting the movement error of the stage 10 from post-pick-up to irradiation, thereby minimizing the variation width of a relative error that is the difference between the movement error at the detection and the actual movement error of the stage at the irradiation when a light-beam is irradiated; adding the detected movement error and the positional shift amount of the lower pattern to calculate the position of forming the upper pattern; and irradiating a light-beam based on the position, thereby enabling a stable performance of an overlapped drawing even for the positional shift caused by the movement error of the stage 10 without complicating the optical system.

Description

  The present invention relates to a drawing apparatus and a drawing method for drawing a wiring pattern or the like on a semiconductor substrate, a liquid crystal substrate, a printed wiring board, or the like placed on a stage that moves relative to an optical head of the drawing apparatus. In particular, the present invention relates to a technique effective for performing exposure while performing alignment based on a pattern previously formed in a lower layer.

  Conventionally, photolithography for patterning a resin or metal wiring into a predetermined pattern shape on the surface of a substrate such as a semiconductor wafer, a liquid crystal substrate, or a printed wiring board (hereinafter simply referred to as a substrate) coated with a photosensitive material. Various exposure apparatuses using technology have been proposed. Then, using such an exposure apparatus, modules and circuit boards are manufactured by sequentially laminating metal wirings and the like.

  Usually, when an exposure pattern is formed on these substrates, overlay exposure is performed in which an upper exposure pattern is positioned and superimposed on a lower exposure pattern. In overlay exposure, the substrate may be deformed and deformed by performing various heat treatments after the exposure pattern in the lower layer is exposed. And the position shift of the lower layer exposure pattern resulting from a deformation | transformation of a board | substrate arises. Therefore, when the upper exposure pattern is exposed, unless the position of the upper exposure pattern is corrected with respect to the lower exposure pattern, the position of the superimposed upper exposure pattern is shifted from the lower exposure pattern.

  Further, when exposure is performed while moving the substrate while being held on the stage, the straightness varies (hereinafter referred to as a movement error) depending on the accuracy of the moving mechanism that moves the stage. Therefore, in order to overlay and expose the upper layer exposure pattern to the lower layer exposure pattern while moving the stage, the displacement of the upper layer exposure pattern relative to the lower layer exposure pattern due to substrate deformation and stage movement error is corrected. Thus, it is necessary to perform overlay exposure. For this reason, there is a technique in which the substrate surface held on the stage is imaged, the positional deviation of the lower exposure pattern is calculated, and the exposure position of the upper exposure pattern is corrected for exposure.

  For example, in Patent Document 1, in the moving direction of a moving color filter substrate, imaging that images the near side of an exposure position via a projection lens for projecting light modulated by a micromirror device onto the color filter substrate A technique is disclosed in which an exposure pattern is exposed while positioning is performed on black matrix pixels provided in advance on a color filter substrate. By using the exposure apparatus having such a configuration, it is possible to detect a stage movement error at a position close to the exposure position.

  Further, for example, in Patent Document 2, a CCD camera is provided with an imaging position at the front side of an exposure position by DMD (Digital Micromirror Device: registered trademark of Texas Instruments) in the moving direction of the moving color filter substrate. ing. Then, the reference position set in the reference function pattern (lower layer pattern) formed in advance on the color filter substrate is imaged and detected. By controlling the driving of the DMD with reference to the reference position at the time of imaging to form an image of the functional pattern (upper layer pattern), the overlay accuracy of the functional pattern is improved.

JP 2006-330622 A JP 2006-178056 A

  However, in an exposure apparatus such as that disclosed in Patent Document 1, an imaging unit that images the front side of an exposure position is provided via a projection lens for projecting light modulated by a micromirror device onto a color filter substrate. In order to observe the light, it is necessary to use a light source having a wavelength that does not expose the resist applied to the surface of the color filter substrate. Therefore, in order to adopt a common optical system, it is necessary to design so that images can be obtained on the same imaging surface for different wavelengths, and the optical design becomes complicated, which is not practical.

  In an exposure apparatus such as Patent Document 2, a DMD and a CCD camera can be provided independently by adopting a CCD camera that captures the front side of the exposure position by DMD in the moving direction of the color filter substrate. Compared to an exposure apparatus such as Patent Document 1, optical design is facilitated. However, as long as the imaging position is the front side of the exposure position, even if a stage movement error is detected, stable pattern overlay accuracy has not been achieved.

  This is because, as the distance between the imaging position and the exposure position becomes longer with respect to the stage movement error whose cycle and phase are unknown, the stage movement error detected at the imaging position and the exposure that is actually exposed The fluctuation range of the relative error with the movement error of the stage at the position becomes large, and stable overlay exposure cannot be performed. In addition, since the stage movement error varies with each exposure operation, the difference between the position of the lower exposure pattern captured before the exposure position and the position of the lower exposure pattern at the exposure position differs for each exposure operation. There is a problem that it fluctuates.

  The present invention has been made in view of the above problems, and does not complicate the design of the optical system, reduces the fluctuation range of the relative error between the movement error during detection and the movement error during exposure, and enables stable overlay drawing. It is the drawing apparatus and drawing method for performing.

  In order to achieve the above object, the present invention horizontally holds a substrate on which a lower layer pattern is formed in advance, and moves the stage while holding the substrate, and a drawing planned area of the substrate held on the stage. A light irradiation unit that irradiates a light beam according to the drawing data of the upper layer pattern, and a drawing target region before the light beam is irradiated to the drawing target region of the substrate held on the stage that moves relative to the light irradiation unit. The position of the imaging unit that images the formed lower layer pattern and the stage that moves relative to the light irradiation unit is detected as a first movement error together with the imaging by the imaging unit, and the light irradiation unit after imaging by the imaging unit By the movement error detection unit that detects the position of the stage as the second movement error before the light beam is irradiated by the light irradiation unit according to the drawing data of the upper layer pattern. A control unit that controls drawing, and the control unit acquires a positional shift amount of the lower layer pattern in the image based on the lower layer pattern included in the image acquired by the imaging unit, and the position of the lower layer pattern in the image By subtracting the first movement error from the deviation amount, the lower layer pattern positional deviation amount, which is the deviation of the lower layer pattern on the substrate, is calculated, and by adding the second movement error to the lower layer pattern positional deviation amount on the substrate, the first movement error is calculated. (2) The upper layer pattern formation position with respect to the lower layer pattern at the time of detection of the movement error is calculated, and the drawing by the light irradiation unit is controlled based on the upper layer pattern formation position.

  In the invention configured as described above, the control unit calculates the amount of positional shift of the lower layer pattern on the substrate at the time of imaging from the lower layer pattern image captured by the imaging unit and the first movement error detected at the time of imaging. To do. Thereby, the shift of the lower layer pattern due to the deformation of the substrate can be calculated in advance between the time of imaging and the time of irradiation.

  The movement error detection unit detects a second movement error of the stage that moves between the time when the light irradiation unit is irradiated with the light beam after the lower layer pattern is captured by the imaging unit. The control unit can calculate the formation position of the upper layer pattern with respect to the lower layer pattern when the second movement error is detected from the amount of positional deviation of the lower layer pattern and the detected second movement error. Thereby, the stage movement error can be detected in a state closer to the position where the light beam is irradiated than the position where the stage is imaged, and the upper layer relative to the lower layer pattern at the position close to the position where the light beam is irradiated. The pattern formation position can be calculated.

  In this way, by calculating the formation position of the upper layer pattern with respect to the lower layer pattern at a position close to the position irradiated with the light beam, the distance that the stage moves to the position irradiated with the light beam is shortened, and the movement error detection unit The fluctuation range of the relative error, which is the difference between the second movement error detected in step 1 and the actual stage movement error during irradiation when the light beam is emitted from the light irradiation unit, can be reduced, so that it matches the lower layer pattern. Thus, stable drawing of an upper layer pattern such as a wiring pattern can be performed.

  In addition, since the light irradiation unit, the imaging unit, and the movement error detection unit are provided independently, it is possible to prevent the optical system from becoming complicated by performing independent design. This facilitates the design of the optical system.

  Further, in the drawing apparatus according to the present invention, the movement error detection unit controls the drawing by the light irradiation unit based on the time required for the control unit to calculate the formation position of the upper layer pattern and the formation position of the upper layer pattern. The second movement error is detected before the light beam is irradiated by the light irradiation unit in accordance with the total time required.

  In the invention thus configured, the movement error detection unit detects the second movement error by the light irradiation unit based on the time required for the control unit to calculate the formation position of the upper layer pattern and the formation position of the upper layer pattern. This is performed in accordance with the total time required for controlling drawing. Therefore, the detection of the second movement error can be made as close as possible at the time of irradiation when the light beam is irradiated by the light irradiation unit. Therefore, the fluctuation range of the relative error, which is the difference between the second movement error detected by the movement error detection unit and the actual stage movement error at the time of irradiation when the light beam is emitted from the light irradiation unit, is further reduced. Therefore, it is possible to perform overlay drawing of the upper layer pattern on the stable lower layer pattern.

  In the drawing apparatus according to the present invention, the light irradiation unit includes an irradiation position shift mechanism that relatively shifts the optical path of the light beam in a direction orthogonal to the direction in which the stage travels, and the control unit includes the irradiation position shift mechanism. And the drawing of the upper layer pattern is controlled by shifting the optical path of the light beam based on the formation position of the upper layer pattern. In the invention configured as described above, the control unit controls the irradiation position shift mechanism to shift the optical path of the light beam based on the formation position of the upper layer pattern, thereby drawing the upper layer pattern in accordance with the lower layer pattern. it can.

  The drawing device according to the present invention further includes a storage unit that stores in advance the design data of the lower layer pattern, and the control unit designs the lower layer pattern and the lower layer pattern included in the captured image acquired by the imaging unit. The position of the lower layer pattern of the substrate held on the stage is calculated by image processing using an image generated from data. In the invention configured as described above, in order to calculate the position of the lower layer pattern of the substrate held on the stage in the control unit, the captured image of the lower layer pattern and the image generated from the design data of the lower layer pattern are processed. Thus, the position of the lower layer pattern can be calculated with certainty.

  In the drawing apparatus according to the present invention, the image processing in the control unit is a pattern matching process. In the invention configured as described above, by adopting pattern matching processing as image processing, it is possible to perform alignment between images and reliably calculate the position of the lower layer pattern.

  In order to achieve the above object, the present invention horizontally holds a substrate on which a lower layer pattern has been formed in advance on a stage, and moves the substrate while holding the substrate, and a drawing scheduled area of the substrate held on the stage A light irradiation step of irradiating a light beam in accordance with the drawing data of the upper layer pattern, and a substrate held on the stage in the light irradiation step by forming the lower layer pattern formed in the drawing target region of the substrate held on the stage An imaging step of imaging by the imaging unit before the light beam is irradiated to the drawing planned area, and a position of the stage that moves while holding the substrate are detected as a first movement error in accordance with the imaging in the imaging step, A movement error detection step for detecting the position of the stage as a second movement error after the imaging in the imaging step and before the light beam is emitted in the light irradiation step; and an upper layer pattern And a control step for controlling the drawing in the light irradiation step based on the drawing data of, and the control step is based on the lower layer pattern included in the captured image acquired in the imaging step, and the position of the lower layer pattern in the captured image The amount of displacement is acquired, and the amount of displacement of the lower layer pattern, which is the displacement of the lower layer pattern on the substrate, is calculated by removing the first movement error from the amount of displacement of the lower layer pattern in the captured image. By adding the second movement error to the positional deviation amount, the upper layer pattern formation position with respect to the lower layer pattern when the second movement error is detected is calculated, and the drawing in the light irradiation process is controlled based on the upper layer pattern formation position. It is characterized by.

  In the invention configured as described above, in the control step, the lower layer pattern on the substrate at the time of imaging is determined from the image of the lower layer pattern imaged in the imaging step and the first movement error detected at the time of imaging in the movement error detection step. The amount of positional deviation is calculated. Thereby, the amount of positional deviation of the lower layer pattern due to the deformation of the substrate can be calculated in advance between the time of imaging and the time of irradiation.

  Then, in the movement error detection step, a second movement error of the stage that moves during the period from the imaging of the lower layer pattern in the imaging step to the irradiation of the light beam in the light irradiation step is detected. In the control step, the formation position of the upper layer pattern relative to the lower layer pattern at the time of detection of the second movement error can be calculated from the amount of positional deviation of the lower layer pattern and the detected second movement error. Thereby, it is possible to detect the movement error of the stage in a state where the light beam is closer to the position where the light beam is irradiated than the position where the lower layer pattern is imaged, and the lower layer pattern at a position close to the position where the light beam is irradiated. The formation position of the upper layer pattern with respect to can be calculated.

  In this way, by calculating the formation position of the upper layer pattern with respect to the lower layer pattern at a position close to the position where the light beam is irradiated, the distance that the stage moves to the irradiation position is shortened, and the first detected by the movement error detection step. 2 The variation width of the relative error, which is the difference between the movement error and the actual stage movement error at the time of irradiation when the light beam is irradiated in the light irradiation process, can be reduced. Stable drawing of the upper layer pattern can be performed.

  Further, in the drawing method according to the present invention, the movement error detecting step controls the drawing in the light irradiation step based on the time required to calculate the formation position of the upper layer pattern in the control step and the formation position of the upper layer pattern. The second movement error is detected before the light beam is irradiated in the light irradiation step in accordance with the total time required.

  In the invention configured as above, the second movement error is detected in the movement error detection process, and the light irradiation process is performed based on the time required to calculate the formation position of the upper layer pattern in the control process and the formation position of the upper layer pattern. Is performed in accordance with the total time required for controlling drawing. Thereby, the detection of the second movement error can be made as close as possible to the time of irradiation when the light beam is irradiated in the light irradiation step. Therefore, the formation position of the upper layer pattern with respect to the lower layer pattern at a position closer to the irradiation position can be calculated.

  In the drawing method according to the present invention, the light irradiation step includes an irradiation position shift step of relatively shifting the optical path of the light beam in a direction orthogonal to the direction in which the stage travels, and the control step is an irradiation position shift step. In the above, the drawing of the upper layer pattern is controlled by shifting the optical path of the light beam based on the formation position of the upper layer pattern. In the invention configured as described above, the control step can draw the upper layer pattern in accordance with the lower layer pattern by shifting the optical path of the light beam based on the formation position of the upper layer pattern in the irradiation position shifting step.

  In the drawing method according to the present invention, the control step is held on the stage by image processing using the lower layer pattern included in the captured image acquired in the imaging step and the image generated from the design data of the lower layer pattern. The position of the lower layer pattern of the substrate is calculated. In the invention configured as described above, in order to calculate the position of the lower layer pattern of the substrate held on the stage in the control process, the captured image of the lower layer pattern and the image generated from the design data of the lower layer pattern are processed. Thus, the position of the lower layer pattern can be calculated with certainty.

  In the drawing method according to the present invention, the image processing in the control step is pattern matching processing. In the invention configured as described above, by adopting pattern matching processing as image processing, it is possible to perform alignment between images and reliably calculate the position of the lower layer pattern.

  According to the present invention, the position shift of the lower layer pattern on the substrate due to the deformation of the substrate from the captured image of the lower layer pattern imaged by the imaging unit and the first movement error detected at the time of imaging by the movement error detection unit. The amount can be calculated. Then, from the second movement error detected after the imaging of the lower layer pattern by the imaging unit until the light beam is irradiated by the light irradiating unit, and the position shift amount of the lower layer pattern, it is caused by the movement error of the stage. It is possible to calculate the formation position of the upper layer pattern considering the positional deviation of the lower layer pattern.

  Thus, by calculating the formation position of the upper layer pattern with respect to the lower layer pattern at a position close to the position where the light beam is irradiated, the moving distance of the stage to the irradiation position is shortened, and the first error detected by the movement error detection unit is detected. 2 It is possible to reduce the fluctuation range of the relative error, which is the difference between the movement error and the actual stage movement error when the light beam is irradiated from the light irradiation unit. It is possible to achieve an excellent effect that a drawing apparatus and a drawing method capable of stably drawing the upper layer pattern can be realized.

It is the whole side view seen from the side of the exposure apparatus concerning one Embodiment of this invention. FIG. 2 is an overall plan view of the exposure apparatus shown in FIG. 1 as viewed from above. FIG. 2 is a partially enlarged view of the exposure apparatus of FIG. 1 as viewed from the top and side surfaces. It is a schematic diagram which shows the internal structure of a light irradiation part. It is a schematic diagram which shows the structure of an irradiation position shift mechanism. It is a block diagram which shows the function part in connection with exposure operation with which a control part is provided. It is a figure for demonstrating the position shift of the lower layer pattern in a captured image. It is a figure for demonstrating the position shift of the lower layer pattern on a board | substrate. It is a figure which shows a series of flows of the drawing process which concerns on this invention. It is a figure for demonstrating in detail the flow of a drawing process. It is a figure which shows the conditions of simulation. It is a graph which shows the relative error in each position in simulation.

  FIG. 1 is an overall side view of an exposure apparatus 100 according to an embodiment of the present invention as seen from the side, and FIG. 2 is an overall plan view of the exposure apparatus 100 shown in FIG.

  In FIGS. 1 and 2, for convenience of illustration and description, the Z-axis direction is defined as the vertical direction and the XY plane is defined as the horizontal plane, but is defined for convenience in order to grasp the positional relationship between them. However, each direction described below is not limited.

  The exposure apparatus 100 directly draws a predetermined pattern such as a wiring pattern by irradiating a light beam onto the upper surface of a semiconductor substrate, a glass substrate, a printed wiring board or the like (hereinafter referred to as a substrate) to which a photosensitive material is applied. A drawing device.

  In this exposure apparatus 100, the exposure apparatus 100 includes various constituent elements provided inside the main body formed by attaching the cover 102 to the main body frame 101 and outside the main body frame 101. It has become.

  Inside the main body of the exposure apparatus 100 are mainly a stage 10 that holds the substrate W, a stage moving mechanism 20 that moves the stage 10, a stage position measuring unit 30 that measures the position of the stage 10, and an upper surface of the substrate W. The light irradiation unit 40 for irradiating the light beam, the imaging unit 50 for imaging the drawing scheduled area on the substrate W, the movement error detection unit 60 for detecting the movement error of the stage 10, and the alignment mark on the substrate W are imaged. An alignment camera 70 and a transfer device 80 for carrying in and out the substrate W are included. In addition, the exposure apparatus 100 includes a control unit 90 that is electrically connected to each unit included in the exposure apparatus 100 and controls the operation of each unit.

  The exposure apparatus 100 is provided outside the main body with a cassette mounting section 104 for mounting the substrate storage cassette 103 at a position adjacent to the main body. The substrate storage cassette 103 stores an unprocessed substrate W to be subjected to a drawing process (exposure process), and the substrate W is carried into the main body by the transfer device 80 arranged inside the main body. After the unprocessed substrate W is exposed, the substrate W is unloaded from the main body by the transport device 80 and returned to the substrate storage cassette 103. Delivery of the substrate storage cassette 103 is performed by an external transfer device (not shown).

  The stage 10 has a rectangular outer shape, and a plurality of suction holes (not shown) are formed on the upper surface of the stage 10. These suction holes are connected to a vacuum pump or the like. When the substrate W is placed on the stage 10 by operating the vacuum pump, the substrate W is placed on the upper surface of the stage 10 by the suction pressure of the suction holes. Adsorbed and fixed. That is, the substrate W is fixedly held on the upper surface of the stage 10 while being kept horizontal.

  The stage moving mechanism 20 moves the stage 10 in the main scanning direction (Y-axis direction), the sub-scanning direction (X-axis direction), and the rotation direction around the Z-axis (θ-axis direction). The stage moving mechanism 20 includes a rotating mechanism 11 that rotates the stage 10, a support plate 12 that rotatably supports the stage 10, a sub-scanning mechanism 13 that moves the support plate 12 in the sub-scanning direction, and a sub-scanning mechanism 13. And a main scanning mechanism 15 that moves the base plate 14 in the main scanning direction. The rotation mechanism 11, the sub-scanning mechanism 13, and the main scanning mechanism 15 are electrically connected to the control unit 90 and move the stage 10 in accordance with instructions from the control unit 90.

  The rotation mechanism 11 has a motor constituted by a rotor attached inside the stage 10. A rotary bearing mechanism is provided between the lower surface side of the center portion of the stage 10 and the support plate 12. For this reason, when the motor is operated, the rotor is driven in the θ direction, and the stage 10 rotates within a predetermined angle range around the rotation axis of the rotary bearing mechanism.

  The sub-scanning mechanism 13 includes a linear motor 13a that generates a driving force in the sub-scanning direction by a moving element attached to the lower surface of the support plate 12 and a stator laid on the upper surface of the base plate 14, and a pair extending in the sub-scanning direction. Guide rail 13b. For this reason, when the linear motor 13a is driven, the support plate 12 and the stage 10 move in the sub-scanning direction along the guide rail 13b on the base plate 14.

  The main scanning mechanism 15 includes a linear motor 15a and a pair of guide rails 15b extending between the base plate 14 and the base 105 so as to guide a part of the base plate 14 in the main scanning direction. The linear motor 15 a has a mover attached to the lower surface of the base plate 14 and a stator laid on the base 105. For this reason, when the linear motor 15a is driven, the base plate 14, the support plate 12 and the stage 10 move in the main scanning direction along the guide rail 15b on the base 105. As such a stage moving mechanism 20, a conventionally used XY-θ axis moving mechanism can be used.

  The stage position measurement unit 30 is a mechanism that measures the position of the stage 10. The stage position measurement unit 30 is electrically connected to the control unit 90 and measures the position of the stage 10 in accordance with an instruction from the control unit 90. For example, it can be configured by a mechanism that irradiates the stage 10 with laser light and uses the interference between the reflected light and the emitted light to measure the position of the stage 10. In this case, the stage position measurement unit 30 includes, for example, an emission unit 31 that emits laser light, a beam splitter 33, a beam bender 32, a first interferometer 34, and a second interferometer 35.

The laser light emitted from the emitting unit 31 first enters the beam splitter 32 and is branched into first branched light that goes to the beam bender 33 and second branched light that goes to the second interferometer 35. The first branched light is reflected by the beam bender 33, enters the first interferometer 34, and is irradiated from the first interferometer 34 to the first portion of the stage 10. Then, the first branched light reflected at the first part is incident on the first interferometer 34 again. The first interferometer 34 is a positional parameter corresponding to the position of the first part based on the interference between the first branched light traveling toward the first part of the stage 10 and the first branched light reflected by the first part. Measure.

On the other hand, the second branched light is incident on the second interferometer 35 and the second part of the stage 10 from the second interferometer 35 (however, the second part is a position different from the first part. ). Then, the second branched light reflected at the second part is incident on the second interferometer 35 again. The second interferometer 35 corresponds to the position of the second part based on the interference between the second branched light traveling toward the second part of the stage 10 and the second branched light reflected by the second part of the stage 10. The measured position parameter is measured.

  The control unit 90 receives position parameters corresponding to the position of the first part of the stage 10 and position parameters corresponding to the position of the second part of the stage 10 from each of the first interferometer 34 and the second interferometer 25. To get. Then, the position of the stage 10 is calculated based on each acquired position parameter.

  The light irradiation unit 40 includes a laser oscillator 41 that emits laser light, a laser drive unit 42 that drives the laser oscillator 41, and light (spot beam) emitted from the laser oscillator 41 that is linear light with a uniform intensity distribution. An illumination optical system 43 (line beam) and an optical head 401 that irradiates light onto the upper surface of the substrate W are provided.

  The laser oscillator 41, the laser driving unit 42, and the illumination optical system 43 are provided inside a box 106 that is constructed on the base 105 so as to straddle the stage 10 and the stage moving mechanism 20. Further, the laser oscillator 41, the laser driving unit 42, and the illumination optical system 43 are electrically connected to the control unit 90 and operate according to instructions from the control unit 90.

  A pair of leg members 107 and 108 are erected on both sides of the moving path of the stage 10 above the base 105 so as to face the stage 10 and the stage moving mechanism 20. A beam member 109 is horizontally provided so as to bridge the top portion of the leg member 107, and the box 106 is provided so as to bridge the top portion of each leg member 108 and the upper surface of the beam member 109.

  The optical head 401 is provided on the side surface of the substantially central portion of the beam member 109. The optical head 401 irradiates the upper surface of the substrate W by forming spatial modulation corresponding to the drawing pattern on the light emitted from the laser oscillator 41 and incident via the illumination optical system 43.

  Next, the configuration of the optical head 401 provided in the light irradiation unit 40 will be described with reference to FIG. FIG. 4 is a diagram schematically illustrating a configuration example of the light irradiation unit 40.

  When the laser driving unit 42 operates, the light irradiation unit 40 emits laser light from the laser oscillator 41, and the emitted laser light is introduced into the optical head 401 through the illumination optical system 43.

  The optical head 401 includes an incident portion 44 that introduces light from the laser oscillator 41 into the optical head 401, a spatial light modulation element 45 for modulating the introduced light, and spatial light modulation of light from the incident portion 44. An optical system 46 leading to the element 45 and an irradiation position shift mechanism for shifting the optical axis of the light modulated by the spatial light modulation element 45 and relatively shifting the drawing position on the upper surface of the substrate W in the sub-scanning direction. 47 and a projection optical system 48 that guides light through the irradiation position shift mechanism 47 to the upper surface of the substrate W.

  The spatial light modulation element 45 is a diffraction grating type modulation element, which is manufactured using a semiconductor device manufacturing technique and is a diffraction grating capable of changing the depth of the grating. As the diffraction grating type light modulation element, for example, GLV (Grating Light Valve) (registered trademark of Silicon Light Machines) is used. Since the principle of light modulation by GLV is already known, a detailed description thereof will be omitted.

  The irradiation position shift mechanism 47 shifts the light spatially modulated by the spatial light modulation element 45 according to the drawing pattern along the sub-scanning direction. Details of the irradiation position shift mechanism 47 will be described later.

  The projection optical system 48 includes a focus mechanism 481 including an objective lens 482 and an actuator that moves the objective lens 482 along the optical axis. By moving the objective lens 482 in the Z-axis direction by the focus mechanism 481, the focal position of the light modulated by the spatial light modulator 45 is adjusted. The light whose focal position is adjusted is irradiated on the upper surface of the substrate W, and a photosensitive layer such as a resist on the substrate W is exposed to draw a wiring pattern or the like.

  Next, the irradiation position shift mechanism 47 will be described in detail with reference to FIG. FIG. 5 is a diagram schematically showing the configuration of the irradiation position shift mechanism 47.

  The irradiation position shift mechanism 47 includes one or more optical components, and shifts the optical path of incident light along the sub-scanning direction by changing the position or posture of at least one optical component.

  As shown in FIG. 5, the irradiation position shift mechanism 47 linearly moves two wedge prisms 471 and one wedge prism 471 along the direction of the optical axis L of incident light with respect to the other wedge prism 471. And a wedge prism moving mechanism 472 for movement. The wedge prism 471 is a prism in which an optical surface on which light enters and an optical surface on which light exits are non-parallel. The two wedge prisms 471 have substantially the same structure, for example, the apex angle and the refractive index are both the same.

  The two wedge prisms 471 are fixed to the fixed stage 473 and the movable stage 474, respectively, and the optical surfaces facing each other are parallel to each other and opposite to each other along the direction of the optical axis L of the incident light. Arranged side by side. Each wedge prism 471 is fixed to each stage 473, 474 using a fixed band 475, for example.

  The fixed stage 473 on which one wedge prism 471 is disposed is fixed on the base portion 476. The movable stage 474 on which the other wedge prism 471 is disposed is movable along a pair of guide rails 4721 installed on the base portion 476. Guide rail 4721 is formed on base portion 476 so as to extend along the Z-axis direction.

  The base portion 476 is provided with a ball screw 4723 that is rotated by a rotary motor 4722. The ball screw 4723 extends along the extending direction of the guide rail 4721 and is screwed into the female screw portion of the bracket 4741 of the movable stage 474. In this configuration, when the ball screw 4723 is rotated by the rotary motor 4722, the movable stage 474 moves along the guide rail 4721 in the Z direction.

  That is, the movable stage 474, the guide rail 4721, the rotation motor 4722, and the ball screw 4723 constitute the wedge prism moving mechanism 472 that linearly moves the other wedge prism 471 along the direction of the optical axis L of the incident light. The The wedge prism moving mechanism 472 moves the other wedge prism 471 linearly along the direction of the optical axis L with respect to the one wedge prism 471, thereby moving the direction of the optical axis L of the two wedge prisms 471. The separation distance along is changed.

  In the irradiation position shift mechanism 47 having the above configuration, the path of light incident on the wedge prism 471 is shifted along the X-axis direction by changing the separation distance along the optical axis L of the two wedge prisms 471. be able to. The shift amount Δx is determined according to the distance between the two wedge prisms 471.

  The imaging unit 50 is associated with the optical head 401 and is disposed upstream by a distance determined in the direction in which the optical head 40 moves relative to the substrate W during main scanning. In this embodiment, the optical head 401 is fixedly installed on the right side surface in FIG. That is, the imaging unit 50 is installed on the side surface of the optical head 401 on the transport device 80 side in the direction in which the optical head 401 moves relative to the stage 10 as the stage 10 moves in the main scanning direction. .

  Specifically, for example, a light source configured by LEDs, a lens barrel, an objective lens, and a CCD image sensor configured by a linear image sensor (one-dimensional image sensor) are provided. Note that the wavelength of the light source employed in the imaging unit 50 is a wavelength at which the resist on the substrate W is not exposed.

  Then, the drawing target area which is the area on the substrate W to be drawn by the corresponding optical head 401 is imaged. Accordingly, before the light irradiation unit 40 irradiates the light drawing unit 40 with the light beam on the drawing area on the substrate W placed on the stage 10 moving in the main scanning direction, the lower layer pattern formed in the drawing area is imaged. be able to. Note that the imaging unit 50 is electrically connected to the control unit 90, acquires imaging data in response to an instruction from the control unit 90, and transmits the acquired imaging data to the control unit 90.

  The movement error detection unit 60 includes a scale pattern 61 formed on the stage 10, an encoder head 62, and an encoder movement mechanism 63 that enables the encoder head 62 to move in the sub-scanning direction. Then, horizontal movement errors of the stage 10 such as variations in straightness caused by movement of the stage 10 in the main scanning direction are sequentially detected.

  The scale pattern 61 is formed on the upper end of the stage 10 so as to extend in the main scanning direction at the side end portion of the stage 10 that is not on the substrate W placed thereon. Is substantially equal to the length of the stage 10. The scale pattern 61 can be formed on the glass surface by hard chromium vapor deposition or the like by various photolithography manufacturing methods.

  The encoder head 62 is provided on the side of the optical head 401 on the surface of the beam member 109 to which the optical head 401 is attached, on the side where the optical head 401 is installed.

  The encoder moving mechanism 63 is disposed between the encoder head 62 and the beam member 109. The encoder moving mechanism 63 includes a linear motor (not shown), a pair of guide rails laid on the beam member 109 and extending in the sub-scanning direction, and a support plate that fixedly supports the encoder head 62 from the side surface. Then, the linear motor is driven to generate a propulsive force in the sub-scanning direction by the mover and the stator laid between the support plate and the beam member 109, and the support plate is moved in the sub-scanning direction along the guide rail. By doing so, the encoder head 62 is moved in the sub-scanning direction.

  The movement error detection unit 60 will be described in detail with reference to FIG. FIG. 3A is a view of the scale pattern 61 formed on the stage 10 as viewed from above. As shown in FIG. 3 (a), the scale pattern 61 has one X scale XS formed linearly in the Y-axis direction and linearly spaced in the X-axis direction so as to be orthogonal to the X scale XS. Y scale YS formed in a plurality of short lines. As the stage 10 moves in the main scanning direction, the scale pattern 61 passes below the encoder head 62 provided on the beam member 109, and the encoder head 62 detects the scale pattern 61.

  The detection of the scale pattern 61 by the encoder head 62 will be described with reference to FIG. FIG. 3B is a schematic view of the scale pattern 61 formed on the encoder head 62 and the stage 10 as viewed from the X-axis direction. The beam member 109 and the encoder moving mechanism 63 are not shown.

  The encoder head 62 has sensitivity in two axial directions (XY directions) orthogonal to each other, and measures the position of the stage 10 by utilizing diffraction and interference of light striking the scale pattern 61. The encoder head 62 includes a light source 621 that irradiates the scale pattern 61 formed on the stage 10 with light L, and a light L that is emitted from the light source 621 is reflected by the scale pattern 61 and receives diffracted light from the X scale XS. One light receiving element 622X and a second light receiving element 622Y that receives the diffracted light from the Y scale YS are provided.

  The first light receiving element 622X detects the position of the stage 10 in the X-axis direction. A reference position is defined in advance in the X-axis direction. The X scale XS detection signal from the encoder head 62 is analyzed, and the distance in the X axis direction between the reference position in the X axis direction and the detected X scale XS is determined. It can be acquired as a displacement amount. Then, a position obtained by shifting the reference position by the amount of the positional deviation is detected as the position of the stage 10 in the X-axis direction at the time of detection.

  The second light receiving element 622Y detects the position of the stage 10 in the Y-axis direction. The light L emitted from the light source 621 is reflected by the scale pattern 61, and the second light receiving element 622Y receives the diffracted light from the Y scale YS and outputs a signal. Then, by comparing the number of Y scales YS set in advance with the number of detected Y scales YS, the amount of displacement from the original position of the stage 10 can be acquired. Then, a position shifted by the amount of the positional deviation based on the original position of the stage 10 in the Y-axis direction is detected as the position of the stage 10 in the Y-axis direction at the time of detection.

  As described above, the movement error detection unit 60 acquires the position in the X-axis direction and the position in the Y-axis direction of the stage 10 that are horizontal positions of the stage 10 acquired from the encoder head 62 and the scale pattern 61. be able to. The difference between the ideal position, which is the original position of the stage 10, and the horizontal position of the stage 10 acquired by the movement error detector 60 is defined as a horizontal movement error of the stage 10 in the present invention.

  The movement error detection unit 60 is electrically connected to the control unit 90, detects a horizontal movement error of the stage 10 in accordance with an instruction from the control unit 90, and sends the detected movement error to the control unit 90. Send.

  The alignment camera 70 images an alignment mark formed in advance on the upper surface of the substrate W. The alignment camera 70 is installed on the left side surface of the beam member 109 in FIG. In other words, the beam member 109 is installed on the surface opposite to the surface on which the optical head 401 is installed.

  The alignment camera 70 has substantially the same configuration as the imaging unit 50 described above. The CCD image sensor provided in the alignment camera 70 is constituted by, for example, an area image sensor (two-dimensional image sensor).

When the alignment mark is imaged by the alignment camera 70, the substrate W placed on the stage 10 moves below the alignment camera 70, and light emitted from a light source (not shown) is guided to the upper surface of the substrate W. The reflected light is received by the CCD image sensor.
Thereby, the imaging data of the alignment mark formed on the upper surface of the substrate W is acquired.

  The alignment camera 50 is electrically connected to the control unit 90, acquires imaging data in response to an instruction from the control unit 90, and transmits the acquired imaging data to the control unit 90.

  The conveying device 80 is disposed at the right hand end inside the main body surrounded by the cover 102. The transfer device 80 is electrically connected to the control unit 90, and transfers the substrate W between the substrate storage cassette 103 and the stage 10 in accordance with an instruction from the control unit 90. As the transfer device 80, for example, a conventionally known transfer robot can be used.

  The control unit 90 controls the operation of each unit provided in the exposure apparatus 100 while executing various arithmetic processes. The control unit 90 performs various displays such as a CPU that performs various arithmetic processes, a ROM that stores a boot program, a RAM that serves as a work area for the arithmetic processes, a hard disk that stores programs and various data files, and the like. The computer includes an input unit such as a display, a keyboard and a mouse, a data communication unit having a data communication function via a LAN, and the like. When the computer operates in accordance with a program installed in the computer, the computer functions as the control unit 90 of the exposure apparatus 100. In addition, each function part implement | achieved in the control part 90 may be implement | achieved by running a predetermined program with a computer, and may be implement | achieved by exclusive hardware.

  Next, each functional unit related to the exposure operation with the above structure realized by the control unit 90 will be described with reference to FIG. FIG. 6 is a block diagram showing the relationship between each functional unit related to the exposure operation provided in the control unit 90 and the exposure control unit 900 that actually controls the drawing.

  The control unit 90 generates a storage unit 91 for storing various data such as CAD data 911 which is drawing pattern data describing an upper layer pattern to be drawn on the substrate W, and CAD data 911 as a data unit for drawing. A data generation unit 92, a rasterization unit 93 that rasterizes the data generated by the data generation unit 92, a shift amount calculation unit 94 that calculates a shift amount of the lower layer pattern, and a formation that calculates the formation position of the upper layer pattern with respect to the lower layer pattern A position calculation unit 95.

  The storage unit 91 stores CAD data 911 generated using an external CAD or the like as described above, raster data 912 rasterized by the rasterizing unit 93, and the like. In addition to the data described above, data detected by each unit is stored. The CAD 911 is prepared in the storage unit 91 in advance via a recording medium or a communication network prior to a series of processes for the substrate W.

  The data generation unit 92 reads the CAD data 911 from the storage unit 91, divides the CAD data 911 into predetermined unit areas (stripes) for drawing, and transmits the CAD data 911 to the rasterizing unit 93 in units of stripes.

  The rasterization unit 93 performs rasterization for each stripe generated by the data generation unit 92, generates raster format raster data 912, and stores the raster data in the storage unit 91. Thus, when the preparation of raster data 912 for one stripe is completed, the raster data 912 is sent to the exposure control unit 900.

  The deviation amount calculation unit 94 receives the imaging data of the drawing-scheduled area on the substrate W acquired by the imaging unit 50 and the horizontal movement error of the stage 10 detected by the movement error detection unit 60, and enters the drawing-scheduled area. The amount of positional deviation of the formed lower layer pattern with respect to the substrate W is calculated. The positional deviation amount of the lower layer pattern with respect to the substrate W represents a difference between the formation position of the lower layer pattern formed on the substrate W and the design position of the lower layer pattern on the substrate W.

  The positional deviation of the lower layer pattern will be described with reference to FIG. The misalignment of the lower layer pattern is caused by two factors. One is a positional shift caused by a movement error of the stage 10 and the other is a positional shift of a lower layer pattern from a design position on the substrate W caused by deformation of the substrate W or the like. In FIG. 7, the ideal position of the stage 10 and the design position of the lower layer pattern on the substrate W when the position error of the lower layer pattern does not occur due to the movement error of the stage 10 and the deformation of the substrate W described above are indicated by broken lines. . Further, the actual position of the stage 10 and the formation position of the lower layer pattern at that time are indicated by solid lines. In FIG. 7, the optical head 401 and the encoder head 62 are not shown.

  FIG. 7A shows the design position of the lower layer pattern with a broken line. The formation position of the lower layer pattern on the substrate W is indicated by a solid line. At this time, before the drawing processing operation, the stage 10 is stationary and the movement error of the stage 10 described above does not occur. Therefore, the actual position of the stage 10 is also an ideal position and is represented by a solid line.

  On the other hand, the substrate W is deformed due to thermal expansion or the like, and the lower layer pattern previously formed on the substrate W is ΔPX in the X-axis direction and ΔPY in the Y-axis direction from the design position on the substrate W. Only a positional shift has occurred. Therefore, in order to draw the upper layer pattern with high accuracy over the lower layer pattern, it is necessary to correct the positional deviation.

  FIG. 7B shows the ideal position of the stage 10 and the substrate at the time of imaging for imaging the drawing planned area of the substrate W held on the stage 10 that is started in the imaging unit 50 and moves in the Y-axis direction by the imaging unit 50. The design position of the lower layer pattern on W is represented by a broken line. Further, the actual position of the stage 10 at the time of imaging and the formation position of the lower layer pattern on the substrate W are represented by solid lines.

  The calculation of the amount of positional deviation between the design position and formation position of the lower layer pattern calculated from the imaging data will be described with reference to FIG. FIG. 8A shows a case where the one-dimensional image data of the lower layer pattern sent from the image pickup unit 50 is accumulated and generated as two-dimensional image data. Further, FIG. 8B shows that the imaging unit 50 uses lower layer pattern design data stored in advance in the storage unit based on the position of the stage 10 sent from the stage position measurement unit 30 by the control unit 90. This is a design image 520 generated by specifying a position substantially the same as the imaged position and converting it into image data. The imaging data shown in FIG. 8 represents data captured so as to include the lower layer pattern shown in FIG.

  The design image 520 includes a design lower layer pattern 521 such as a wiring pattern. Similarly, the captured image 510 includes a formation lower layer pattern 511 such as a wiring pattern formed in advance on the substrate W.

  A template 522 having a characteristic pattern is extracted from the design image 520. At the same time, the design reference point 523 is set in the template 522, and the coordinates of the design reference point 523 are stored. This is the design position. Although the design reference point 523 is set at the upper left of the template 522, the present invention is not limited to this, and a point that can be specified in the template 522 (for example, the center of gravity) may be set as the design reference point. .

  Subsequently, a so-called pattern matching process is performed on the captured image 510 using the template 522 to obtain a matching region 512 that is a position having a high matching degree. That is, the upper left point of the matching area 512 is the detection reference point 513.

  Differences between the design reference point 523 and the detection reference point 513 in the X direction and the Y direction are the positional deviation amount ΔIPX in the X axis direction and the positional deviation amount ΔIPY in the Y axis direction of the formation position with respect to the design position of the lower layer pattern in the captured image. I want.

  However, the imaging data obtained by imaging by the imaging unit 50 is acquired by imaging the substrate W held on the stage 10. That is, when the stage 10 is displaced due to the movement error, the imaging data acquired by imaging the substrate W held on the stage 10 includes the movement error of the stage 10 at the time of imaging and the movement on the substrate W. The position shift of the lower layer pattern from the design position is superimposed. Therefore, it is necessary to subtract the movement error of the stage 10 at the time of imaging from the amount of positional deviation of the lower layer pattern obtained from the captured image.

  Here, as described above, the movement error of the stage 10 can be detected by the encoder head 62 and the scale pattern 61. Specifically, regarding Y scale YS, ΔISY is obtained by comparing the number of Y scale YS set in advance with the number detected at the time of imaging. On the other hand, regarding the X scale XS, the distance in the X axis direction between the reference position of the stage 10 in the X axis direction and the X scale XS detected at the time of imaging can be acquired as ΔISY. ΔISX and ΔISY represent the movement error of the stage 10 during imaging.

  Therefore, in order to calculate the positional deviation amount of the lower layer pattern formed in the drawing planned area from the design position on the substrate W, ΔIPX, ΔIPY which are the positional deviation amounts of the lower layer pattern in the captured image calculated from the imaging data. Then, the movement error ΔISX in the X-axis direction and the movement error ΔISY in the Y-axis direction of the stage 10 during imaging may be subtracted (ΔIPX−ΔISX, ΔIPY−ΔISY).

  In this way, the Y-axis positional deviation amount ΔPY and the X-axis positional deviation amount ΔPX can be calculated as the positional deviation amounts of the lower layer pattern on the substrate W. Then, the X-axis position shift amount ΔPX and the Y-axis position shift amount ΔPY of the lower layer pattern on the substrate W calculated by the shift amount calculation unit 94 are sent to the formation position calculation unit 95. Note that the X-axis positional deviation amount ΔPX and the Y-axis positional deviation amount ΔPY of the lower layer pattern on the substrate W are positional deviations caused only by the deformation of the substrate W, and therefore at least during the drawing process, the drawing scheduled area on the substrate W The X-axis positional deviation amount ΔPX and the Y-axis positional deviation amount ΔPY of the lower layer pattern do not change.

  The formation position calculation unit 95 uses the X-axis position shift amount ΔPX and Y-axis position shift amount ΔPY of the lower layer pattern on the substrate W calculated by the shift amount calculation unit 94 and the timing set in advance by the movement error detection unit 60. The detected movement error of the stage 10 is received, and the formation position of the upper layer pattern with respect to the lower layer pattern is calculated.

  Here, calculation of the formation position of the upper layer pattern with respect to the lower layer pattern will be described with reference to FIG. FIG. 7C shows the movement error detector 60 at a preset timing between the time when the drawing area on the substrate W is imaged by the imaging section 50 and the time when the light area is irradiated with the light beam. The ideal position of the stage 10 and the design position of the lower layer pattern on the substrate W at the time of detection when the movement error of the stage 10 is detected are represented by broken lines, and the actual position of the stage 10 and the formation position of the lower layer pattern on the substrate W at the time of detection Is represented by a solid line.

  The formation position of the upper layer pattern with respect to the lower layer pattern can be said to be information in which the X-axis positional deviation amount PX and the Y-axis positional deviation amount PY of the lower layer pattern on the substrate W and the movement error of the stage 10 are superimposed. Therefore, the X-axis position shift amount PX and Y-axis position shift amount PY of the lower layer pattern on the substrate W calculated by the shift amount calculation unit 94 and the stage 10 detected by the movement error detection unit 60 at a preset timing. The movement error ΔDSX in the X axis direction and the movement error ΔDSY in the Y axis direction are added together (ΔPX + ΔDSX, ΔPY + ΔDSY).

  The movement error of the stage 10 is caused by shifting from the original upper layer pattern formation position by the positional deviation amount ΔPX + ΔDSX in the X-axis direction of the upper layer pattern and the positional deviation amount ΔPY + ΔDSY in the Y-axis direction with respect to the lower layer pattern calculated by the addition. And the formation position of the upper layer pattern with respect to the lower layer pattern for correcting the positional deviation from the design position of the lower layer pattern on the substrate W can be calculated. The formation position of the upper layer pattern with respect to the lower layer pattern is calculated as a position in the XY plane composed of the X axis and the Y axis. Then, the formation position of the upper layer pattern is transmitted to the exposure control unit 900.

  Further, the formation position calculation unit 95 adds four rules to add up the X-axis positional deviation amount ΔPX and Y-axis positional deviation amount ΔPY of the lower layer pattern, and the movement error ΔDSX in the X-axis direction and the movement error ΔDSY in the Y-axis direction of the stage 10. Perform arithmetic processing. For this reason, it is possible to shorten the time for the arithmetic processing as compared with the processing in the deviation amount calculation unit 94 described above.

  The exposure control unit 900 receives the formation position of the upper layer pattern and the raster data 912 sent from the formation position calculation unit 95. Then, when the drawing planned area imaged before drawing passes below the optical head 401, the spatial light modulator 45 is controlled based on the raster data 912, and based on the X position of the upper layer pattern formation position with respect to the lower layer pattern. The irradiation position shift mechanism 47 is controlled.

  Specifically, the relative distance between the two wedge prisms 471 constituting the irradiation position shift mechanism 47 is changed according to the X position. Then, the optical path of the light beam shifts in the X-axis direction. That is, the drawing position on the substrate W can be relatively shifted in the sub-scanning direction. In this way, the upper layer pattern can be drawn while aligning with the lower layer pattern in the X-axis direction.

  Further, the timing of spatially modulating the incident light of the spatial light modulator 45 according to the raster data 912 is controlled based on the Y position of the upper layer pattern formation position with respect to the lower layer pattern, so that the drawing position is relatively in the main scanning direction. Can be shifted. In this manner, the upper layer pattern can be drawn while aligning with the lower layer pattern in the Y-axis direction.

  Subsequently, an example of the operation of the exposure apparatus 100 described above will be described with reference to FIGS. FIG. 9 is a flowchart for explaining the overall processing flow related to the exposure processing. FIG. 10 is a flowchart for explaining in detail the flow of the drawing process.

  The exposure apparatus 100 issues an operation command to the transport apparatus 80 from the control unit 90, takes out the substrate W from the substrate storage cassette 103 storing the substrate W, and carries it into the exposure apparatus 100. Then, the substrate W carried into the exposure apparatus 100 is placed on the upper surface of the stage 10 (step S11). Then, the stage 10 on which the vacuum pump is operated and the substrate W is placed fixes the substrate W to the upper surface of the stage 10 by suction by suction pressure. Before placing the substrate W carried out of the substrate storage cassette 103 on the stage 10, a pre-arrangement process may be performed.

  Further, the substrate W carried out of the substrate storage cassette 103 has a lower layer pattern formed in advance on the surface of the substrate W by another exposure apparatus or the like in another processing step. Then, alignment marks for aligning the posture of the substrate W are formed at the four corners of the substrate W. The alignment marks are not limited to the four corners of the substrate W, and a plurality of alignment marks may be formed.

  The stage 10 holding the substrate W on its upper surface moves to the alignment region when the stage moving mechanism 20 operates based on an operation command from the control unit 90. Then, the exposure apparatus 100 performs an alignment process (positioning process) for adjusting the relative position between the substrate W placed on the stage 10 and the optical head 401 (step S12).

  When the substrate W is placed on the stage 10, it is placed at a substantially predetermined position. However, in many cases, the positional accuracy is not sufficient for drawing a fine pattern. For this reason, alignment processing is performed to finely adjust the position and inclination of the substrate W to improve the accuracy of the subsequent drawing processing.

  In the alignment process, the alignment camera 70 images each of the alignment marks formed at the four corners of the upper surface of the substrate W. The control unit 90 extracts each alignment mark in the image acquired by the alignment camera 70. Then, based on the position of each alignment mark, as the amount of deviation from the ideal position of the substrate W, the amount of deviation in the X-axis direction, the amount of deviation in the Y-axis direction, and the amount of deviation in the θ direction around the Z-axis are calculated. Then, the controller 90 corrects the position of the substrate W by driving the rotation mechanism 11, the sub-scanning mechanism 13, and the main scanning mechanism 15 so as to reduce the calculated shift amount.

  Subsequently, the exposure apparatus 100 performs a drawing process on the substrate W on which the alignment process has been performed (step S13). The details of the drawing process will be described later, but here, the flow of the drawing process in this embodiment will be briefly described.

  The exposure apparatus 100 draws an upper layer pattern on the upper surface of the substrate W by irradiating a light beam from the optical head 401 toward the upper surface of the substrate W while moving the stage 10 in the main scanning direction and the sub-scanning direction.

  Specifically, the stage 10 is moved in the main scanning direction by operating the main scanning mechanism 15 in accordance with an instruction from the control unit 90. Thereby, the substrate W can be moved relative to the optical head 401 along the main scanning direction. When a drawing scheduled area for one stripe on the substrate W passes below the optical head 401, drawing for one stripe is performed on the surface of the substrate W.

  When the drawing for one stripe is completed, the control unit 90 operates the main scanning mechanism 15 to move the stage 10 along the main scanning direction to the original position where the drawing of the stripe is started. Further, the control unit 90 operates the sub-scanning mechanism 13 to move the stage 10 by a distance corresponding to the width of one stripe along the sub-scanning direction. When the movement in the sub-scanning direction is completed, drawing is performed while the stage 10 is scanned again in the main scanning direction.

  Then, an area for one stripe is further drawn next to the drawing area for one stripe previously drawn. Thus, the upper layer pattern is drawn on the entire surface of the substrate W by repeatedly performing the movement in the main scanning direction and the movement in the sub-scanning direction.

  When the drawing process on the entire area of the substrate W is completed, the control unit 90 operates the stage moving mechanism 20 to move the stage 10 on which the drawing-processed substrate W is placed to the carry-out position. Then, the operation of the vacuum pump is stopped, and the suction holding on the stage 10 is released. In response to the operation command of the control unit 90, the transport device 80 unloads the substrate W on which drawing processing has been performed from the upper surface of the stage 10 from the exposure device 100 and transports it to the substrate storage cassette 103 (step S14).

  Next, the drawing process (step S13) will be described in detail. FIG. 10 is a diagram for explaining the flow of the drawing process in detail.

  The stage moving mechanism 20 operates according to the operation command from the control unit 90, and the stage 10 moves to the drawing start position (step S101). The drawing start position is determined based on the writing position of the substrate W placed on the stage 10, and is stored in the control unit 90.

  Next, raster data 912 for one stripe is sent from the rasterizing unit 93 of the control unit 90 to the exposure control unit 900. Upon confirming that the raster data 912 for one stripe has been received, the exposure control unit 900 operates the main scanning mechanism 15 and starts moving the stage 10 in the main scanning direction (step S102). At this time, while the light beam is irradiated from the optical head 401 toward the substrate W, the stage 10 is controlled to move in the main scanning direction at a constant speed. The moving speed of the stage 10 is determined based on the photosensitive characteristics of the resist applied on the substrate W and the light amount of the light beam emitted from the optical head 401.

  The control unit 90 also issues an operation command to the stage position measurement unit 30. The stage position measurement unit 30 continuously irradiates laser light toward the stage 10 moving in the main scanning direction, and continuously detects the position of the stage 10 in the main scanning direction from the interference between the reflected light and the emitted light. To the control unit 90. Therefore, the control unit 90 can always grasp the position of the stage 10 in the main scanning direction during the drawing process.

  When scanning along the main scanning direction of the stage 10 is started, the control unit 90 issues an operation command to the imaging unit 50. The imaging unit 50 images the drawing planned area on the substrate W held by the stage 10 that moves in the main scanning direction in response to the operation command, and acquires imaging data of the lower layer pattern formed in the drawing scheduled area (step S103). ). However, the imaging unit 50 is arranged upstream from the optical head 401 by a predetermined distance in the main scanning direction. Accordingly, in the imaging unit 50, the stage 10 is moved by the distance with respect to the optical head 401, and imaging data captured before the drawing target area on the substrate W to be drawn is drawn by the optical head 401. Will be acquired.

  Here, in the present embodiment, since the imaging unit 50 employs a one-dimensional image sensor, imaging data captured in one dimension is sequentially transmitted to the control unit 90. Then, the control unit 90 combines the one-dimensional imaging data to generate a two-dimensional image. In this embodiment, the time when the one-dimensional imaging data including the position of the center of gravity of the generated two-dimensional image is acquired is set as the time of imaging.

  In parallel with this, the control unit 90 issues an operation command to the movement error detection unit 60 to operate the encoder head 62. The encoder head 62 irradiates light toward the scale pattern 61 formed on the stage 10, and can continuously detect a movement error of the stage 10 using light diffraction and interference. Then, the movement error of the stage 10 detected at the timing (first detection timing) adjusted at the time of imaging by the imaging unit 50 is detected as the first movement error (step S104). More precisely, the movement error of the stage 10 detected continuously is temporarily stored, and the movement error of the stage 10 stored at the timing matched at the time of imaging is acquired as the first movement error.

  At this time, the movement error of the stage 10 detected by the encoder head 62 detects the movement error of the stage 10 below the encoder head 62. However, the movement error of the stage 10 occurs uniformly over the entire stage 10. Therefore, even a movement error of the stage 10 detected under the encoder head 62 can be treated as a movement error occurring with respect to the entire stage 10. That is, it can be said that the movement error of the stage 10 detected below the encoder head 62 is equivalent to the movement error of the stage 10 below the imaging unit 50 or the optical head 401 at the same time. Then, the movement error detection unit 60 transmits the movement error of the stage 10 detected by the encoder head 62 to the control unit 90.

  The deviation amount calculation unit 94, which is a functional unit related to exposure of the control unit 90, generates the imaging data sent from the imaging unit 50 as a two-dimensional image and the first movement sent from the movement error detection unit 60. Get the error. The deviation amount calculation unit 94 calculates the positional deviation amount of the lower layer pattern in the two-dimensional image using the two-dimensional image generated from the one-dimensional imaging data sent from the imaging unit 50.

  At this time, the difference between the design position of the lower layer pattern in the two-dimensional image and the formation position of the lower layer pattern actually formed on the substrate W is calculated as the positional deviation amount of the lower layer pattern. The positional deviation amount includes a positional deviation amount ΔIPX in the X-axis direction and a positional deviation amount ΔIPY in the Y-axis direction as shown in FIG.

  Then, by using the first movement error of the stage 10 acquired in step S104, the first movement error is subtracted from the amount of position deviation of the lower layer pattern in the two-dimensional image. The amount is calculated (step S105). The positional deviation amount of the lower layer pattern on the substrate W is calculated as an X-axis positional deviation amount PX as a positional deviation amount in the X-axis direction and a Y-axis positional deviation amount PY as a positional deviation amount in the Y-axis direction.

  Even after the processing in step S103 and step S104 is performed, the stage 10 moves toward the optical head 401 at a constant speed. Then, the movement error of the stage 10 detected by the encoder head 62 at the preset timing (second detection timing) after the imaging by the imaging unit 50 until the light beam is emitted by the optical head 401 is set to the second. It detects as a movement error (step S106).

  Here, detection of the second movement error of the stage 10 will be described. The second detection timing for detecting the second movement error is such that the irradiation position shift mechanism 47 is controlled based on the time required for calculating the formation position of the upper layer pattern, which will be described later, and the calculated formation position of the upper layer pattern, and the light beam is directed to the substrate W. It is determined based on the time required for irradiation. That is, the second movement error is detected before the light beam is irradiated for a time that is the sum of the time for calculating the formation position of the upper layer pattern and the time required to shift the optical path of the light beam based on the formation position. The second detection timing is set in such a manner.

  In this way, by setting the second detection timing, it is possible to detect the movement error of the stage 10 at the closest position closest to the irradiation position where the optical beam 401 is irradiated with the light beam. The movement error detection unit 60 transmits the second movement error detected by the encoder head 62 to the control unit 90.

  The formation position calculation unit 95 sends the X-axis positional deviation amount PX and the Y-axis positional deviation amount PY, which are the positional deviation amounts of the lower layer pattern on the substrate W sent from the deviation amount calculation unit 94, and the movement error detection unit 60. The second movement error detected at the second detection timing is received. The formation position calculation unit 95 detects the X-axis position shift amount PX and the Y-axis position shift amount PY of the lower layer pattern on the substrate W, and the X-axis direction movement errors ΔDSX and Y of the second movement error detected at the second detection timing. By adding the movement error ΔDSY in the axial direction, the positional deviation amount ΔPX + ΔDSX of the upper layer pattern relative to the lower layer pattern and the positional deviation amount ΔPY + ΔDSY in the Y axis direction are calculated.

  Then, a position obtained by shifting the original upper layer pattern formation position by ΔPX + ΔDSX and ΔPY + ΔDSY is calculated as the upper layer pattern formation position with respect to the lower layer pattern (step S107).

  The formation position of the upper layer pattern with respect to the lower layer pattern calculated by the formation position calculation unit 95 is transmitted to the exposure control unit 900. The exposure control unit 900 controls the irradiation position shift mechanism 47 based on the formation position of the upper layer pattern to shift the optical path of the light beam emitted from the optical head 401 in the sub-scanning direction as necessary. In the main scanning direction, the timing at which light is emitted from the optical head 401 is controlled and corrected (step S108).

  Specifically, the formation position of the upper layer pattern with respect to the lower layer pattern sent from the formation position calculation unit 95 includes a formation position in the X-axis direction and a formation position in the Y-axis direction. The exposure control unit 900 operates the irradiation position shift mechanism 47 based on the formation position in the X-axis direction. That is, the two wedge prisms 471 in the irradiation position shift mechanism 47 are relatively separated so that the light beam can be irradiated to the formation position in the X-axis direction of the upper layer pattern sent from the formation position calculation unit 95. Change the distance. Then, the optical path of the light beam shifts in the X-axis direction, and the upper layer pattern can be drawn while accurately aligning with the lower layer pattern in the sub-scanning direction.

  In the main scanning direction, the on / off timing of the spatial light modulator 45 is controlled so that the light beam is irradiated to the formation position in the Y-axis direction of the upper layer pattern sent from the position calculation unit 95. . For example, when the pixel is shifted in the direction in which drawing is delayed in the main scanning direction from the original upper layer pattern formation position due to a movement error of the stage 10 or the like, the timing for turning on the spatial light modulator 45 is delayed by one pixel. Thus, the upper layer pattern can be drawn while accurately aligning the lower layer pattern with respect to the main scanning direction.

  The above operation is performed until drawing for one stripe is completed. When the drawing for one stripe is completed, it is determined whether or not there is a next stripe to be drawn (step S109). If there is a next stripe, the stage moving mechanism 20 responds to an operation signal from the control unit 90. The stage 10 is returned to the start position, and the stage 10 is relatively moved in the sub-scanning direction by one stripe (step S110).

  At the same time, an operation command is also sent from the control unit 90 to the encoder moving mechanism 63, and the encoder head 62 is also relatively moved in the sub-scanning direction (step S111). That is, since the encoder head 62 can move in the sub-scanning direction so as to follow the scale pattern 61 formed on the stage 10, it can continuously detect the movement error of the stage 10 during the drawing process. .

  Then, Steps S102 to S109 are repeated for the adjacent stripe, and when the upper layer pattern is drawn on the entire surface of the substrate W, the drawing process is completed, and the processed substrate W is unloaded from the stage 10 by the transfer device 80. The

  As described above, by providing the imaging unit 50 and the movement error detection unit 60 as in the exposure apparatus 100 of the present invention, first, the amount of positional deviation of the lower layer pattern on the substrate W due to the deformation of the substrate is calculated. Can do. In addition to the imaging unit 50, the movement error detection unit 60 can detect a movement error of the stage 10 due to the movement of the stage 10. That is, by providing the imaging unit 50, the movement error detection unit 60, and the optical head 401 independently, the design of the optical system of each configuration can be simplified.

  In addition, since the timing for detecting the movement error of the stage 10 can be freely set, the position where the movement error of the stage 10 is detected becomes the irradiation position by the optical head 401 if only the minimum time required for each process is secured. It can be practically close to the limit.

  Next, the movement error of the stage 10 on the near side of the exposure position is verified. FIG. 11 is a schematic diagram showing the conditions of this simulation.

  FIG. 11 shows the position of the stage 10 at the time of imaging when the lower layer pattern of the drawing-scheduled area is imaged by the imaging unit 50, the position of the stage 10 at the time of detection when the second movement error is detected by the encoder head 62, and the optical head. Reference numeral 401 denotes a positional relationship with the position of the stage 10 at the time of irradiation when the light beam is irradiated on the drawing scheduled area. Note that a state where the stage 10 is positioned at the time of imaging by the imaging unit 50 and a detection by the encoder head 62 is indicated by a broken line, and a position of the stage 10 at the time of irradiation by the optical head 401 is indicated by a solid line. The illustration of the substrate W placed on the stage 10 is omitted.

  Next, the moving speed of the stage 10 in the main scanning direction is set to 100 [mm / sec]. Further, the distance that the stage 10 moves from when the drawing-scheduled area is imaged by the imaging unit 50 to when the optical head 401 is irradiated with the light beam is 100 [mm]. This means the distance between the optical head 401 and the imaging unit 50, and when the optical head 401 and the imaging unit 50 are provided separately, it depends on the size of the housing of the optical head 401. Therefore, there is a limit in reducing the distance between them. In this simulation, this distance is set to 100 [mm] as described above.

  The simulation is performed by setting the distance D to which the stage 10 moves from the time of detection of the second movement error by the movement error detector 60 to the time of irradiation by the optical head 401 as 10, 20, 30, 50, 70, 100 [mm]. This distance D means how close the stage 10 can detect the movement error of the stage 10 to the position where the optical head 401 irradiates the light beam.

  The encoder head 62 detects a movement error of the stage 10 when the stage 10 passes thereunder. However, unlike the imaging unit 50, there is no need to consider the distance between the optical head 401. This is because the encoder head 62 can detect the movement error of the stage 10 at an arbitrary position by adjusting the timing of detecting the movement error of the stage 10.

  In this simulation, the movement error generated in the stage 10 is a sine wave. Since the movement error of the stage 10 occurs irregularly, the period and phase cannot be specified in advance. However, all signals can be divided into sine waves of each frequency. This is known by Fourier's theorem and will not be described. Therefore, in this simulation, a simulation is performed for a case where one of horizontal movement errors caused by the movement of the stage 10 occurs at a frequency of 5.0 [Hz] and an amplitude of 1.0 [mm].

  Under the conditions described above, when only the imaging unit 50 that images the lower layer pattern is used and the movement error of the stage 10 is detected at the time of imaging, the second described above using the movement error detection unit 60 as in the present invention. A simulation is performed for the fluctuation range of the relative error between the movement error at the time of detection of the stage 10 and the actual movement error of the stage 10 at the time of irradiation with the light beam when the movement error of the stage 10 is detected at the detection timing. The results are shown in FIG. The relative error represents the amount of positional deviation of the upper layer pattern with respect to the position of the lower layer pattern when the upper layer pattern forming position is corrected using the detected movement error of the stage 10.

  Therefore, if the movement error of the stage 10 at the time of detection and the movement error at the time of irradiation when the optical head 401 emits the light beam completely coincide with each other, the relative error becomes zero, and the positional deviation of the upper layer pattern with respect to the lower layer pattern does not occur. . On the other hand, when the movement error of the stage 10 at the time of detection and the actual movement error at the time of irradiation are opposite values, the upper layer pattern is corrected in the reverse direction with respect to the lower layer pattern. Accordingly, as the relative error increases, the positional deviation of the upper layer pattern with respect to the lower layer pattern increases, and the overlay drawing accuracy decreases.

  FIG. 12 shows a relative error when the movement error of the stage 10 is detected under the above-described conditions, and the phase of the movement error is shifted from 0 degrees to 360 degrees.

  When the relative error between the movement error of the stage 10 detected at the position (D = 100 mm) imaged by the imaging unit 50 and the movement error of the stage 10 at the time of irradiation by the optical head 401 is seen, the phase is 0 degree. The relative error is 0 mm at the minimum, and the relative error is 2.0 mm at the maximum when the phase is 90 degrees. The relative error becomes zero, indicating that the movement error detected at the time of imaging is the same as the movement error detected at the time of irradiation. In addition, the relative error is maximized because the difference between the movement error detected at the time of imaging and the movement error detected at the time of irradiation is maximized.

  If the phase is 0 degree, the upper layer pattern relative to the lower layer pattern is calculated by calculating the formation position of the upper layer pattern using the movement error of the stage 10 detected at the time of imaging and performing drawing based on the position. Therefore, the overlay drawing can be performed satisfactorily. In other words, overlay drawing can be performed satisfactorily by calculating and correcting the formation position of the upper layer pattern using only the imaging data captured by the imaging unit 50.

  However, when the phase is 90 degrees, if the upper layer pattern formation position is calculated using the movement error of the stage 10 detected at the time of imaging and drawing is performed based on the position, the direction to be originally corrected is determined. Will be corrected in the opposite direction. In this case, compared to the case where drawing is performed without taking the movement error of the stage 10 into consideration, the accuracy of overlay drawing is deteriorated twice.

  In other words, the drawing accuracy is improved when the phases match, but the drawing accuracy is deteriorated when the phase is largely shifted, so that stable overlay drawing cannot be performed.

  On the other hand, when the distance D between the position of the stage 10 when the second movement error is detected by the encoder head 62 and the position where the optical beam 401 is irradiated with the light beam is D = 10 mm, the phase is 99. At degrees, the relative error is a minimum of 0, and when the phase is 10 degrees, the relative error is a maximum of 0.31 mm.

  That is, even when a movement error of the stage 10 that maximizes the relative error occurs, the influence of the movement error can be reduced more reliably than the original stage 10 amplitude of 1.0 mm. Therefore, it is possible to perform overlay drawing of the upper layer pattern on the lower layer pattern with stable accuracy regardless of the phase of the movement error occurring in the stage 10.

Table 1 summarizes the results of simulations under the conditions described above. The maximum value and minimum value of the relative error at each distance D, and the range of the relative error that is the difference between them are shown.

  When the distance D is changed from 10 mm to 100 mm, the fluctuation range (RANGE), which is the difference between the minimum value (MIN) and the maximum value (MAX) of the relative error, becomes smaller as the distance D becomes smaller. . Therefore, the shorter the distance that the stage 10 moves from when the movement error of the stage 10 is detected until the light beam is irradiated by the optical head 401, the stability of the overlay drawing can be stabilized. .

  As described above, the exposure apparatus 100 includes the imaging unit 50 and the movement error detection unit 60, thereby causing the positional shift of the lower layer pattern on the substrate W due to the deformation of the substrate W and the movement of the stage 10. The position shift due to the movement error of the stage 10 can be acquired. At that time, the movement error detection unit 60 can set the timing for detecting the second movement error between the time after the image pickup by the image pickup unit 50 and the time when the optical head 401 irradiates the light beam. The distance that the stage 10 moves from the time of detection to the time of irradiation with the light beam can be shortened.

  As a result, the fluctuation range, which is a possible range of the relative error of the movement error caused by the movement of the stage 10, can be reduced, so that the overlay drawing of the upper layer pattern on the lower layer pattern can be performed with stable accuracy. .

In addition, since the optical head 401 and the encoder head 62 that is the movement error detection unit 60 are provided independently, they can be mounted with independent designs, and the design of the optical system can be prevented from becoming complicated. .
<Modification>

  As mentioned above, although embodiment of this invention has been described, this invention is not restricted to said embodiment, A various deformation | transformation is possible.

  In the above embodiment, the encoder head 62 is used to detect the movement error of the stage 10, but the present invention is not limited to this. For example, as a configuration corresponding to the encoder head 62, a microscope and a CCD image sensor for imaging the scale pattern 61 formed on the substrate surface via the microscope can be used. Then, based on the captured image of the scale pattern 61, image processing such as pattern matching may be performed, and the movement error of the stage 10 may be calculated from the lattice position of the scale pattern 61.

  In the above embodiment, the encoder head 62 is configured to move in the sub-scanning direction in synchronization with the movement of the stage 10 in the sub-scanning direction (X-axis direction). However, the present invention is not limited to this configuration. For example, the encoder head 62 is fixedly arranged by increasing the stage size of the stage 10 in the sub-scanning direction and increasing the width of the scale pattern 61 in this direction (for example, by making it the same length as the diameter of the substrate W). It is also possible to configure as described above.

  In the above embodiment, the optical path of the light beam is corrected using the irradiation position shift mechanism 47 in order to correct the irradiation position of the light beam based on the formation position of the upper layer pattern with respect to the lower layer pattern. It is not limited. For example, the irradiation position of the light beam can be shifted relative to the optical head 401 by moving the stage 10 in the correcting direction based on the calculated formation position of the upper layer pattern.

  The same effect can also be obtained by correcting the drawing data itself to be transmitted to the optical head 401 based on the calculated upper layer pattern formation position.

  Moreover, although the drawing apparatus and method with respect to a semiconductor substrate were demonstrated in the said embodiment, the drawing target object is not restricted to this. For example, the present invention may be used when performing overlay drawing of a printed wiring board, a glass substrate for a flat panel display, a photomask, or the like.

2 Computer 10 Stage 20 Stage moving mechanism 30 Stage position measurement unit 40 Light irradiation unit 47 Irradiation position shift mechanism 50 Imaging unit 60 Movement error detection unit 90 Control unit 94 Deviation amount calculation unit 95 Formation position calculation unit 100 Exposure apparatus W Substrate

Claims (10)

While holding the substrate in which the lower layer pattern is formed in advance horizontally, a stage that can move while holding the substrate,
A light irradiation unit configured to irradiate a light beam in accordance with drawing data of an upper layer pattern with respect to a drawing scheduled region of the substrate held on the stage;
An imaging unit for imaging the lower layer pattern formed in the planned drawing area before the light beam is irradiated onto the drawing target area of the substrate held on the stage that moves relative to the light irradiation unit;
The position of the stage that moves relative to the light irradiating unit is detected as a first movement error together with the imaging by the imaging unit, and the light irradiating unit irradiates the light beam after imaging by the imaging unit. A movement error detector that detects the position of the stage as a second movement error until
A control unit for controlling drawing by the light irradiation unit according to the drawing data of the upper layer pattern,
The controller is
Based on the lower layer pattern included in the image acquired by the imaging unit, the positional deviation amount of the lower layer pattern in the image is acquired, and the first movement error is removed from the positional deviation amount of the lower layer pattern in the image. Calculate the amount of displacement of the lower layer pattern, which is the displacement of the lower layer pattern on the substrate,
By adding the second movement error to the position shift amount of the lower layer pattern on the substrate, the formation position of the upper layer pattern with respect to the lower layer pattern at the time of detection of the second movement error is calculated,
A drawing apparatus that controls drawing by the light irradiation unit based on a formation position of the upper layer pattern.   The movement error detection unit combines a time required for the control unit to calculate the formation position of the upper layer pattern and a time required to control drawing by the light irradiation unit based on the formation position of the upper layer pattern. 2. The drawing apparatus according to claim 1, wherein the second movement error is detected before the light irradiation unit emits the light beam according to a predetermined time. The light irradiation unit includes an irradiation position shift mechanism that relatively shifts the optical path of the light beam in a direction orthogonal to a direction in which the stage travels,
The control unit controls the drawing of the upper layer pattern by controlling the irradiation position shift mechanism and shifting the optical path of the light beam based on the formation position of the upper layer pattern. The drawing apparatus according to claim 2. A storage unit for storing design data of the lower layer pattern in advance;
The control unit determines the position of the lower layer pattern of the substrate held on the stage by image processing using a lower layer pattern included in the captured image acquired by the imaging unit and an image generated from the design data. The drawing apparatus according to claim 1, wherein the drawing apparatus calculates the drawing apparatus.   The drawing apparatus according to claim 4, wherein the image processing in the control unit is pattern matching processing. While holding the substrate on which the lower layer pattern is formed in advance horizontally on the stage, the moving step of holding and moving the substrate;
A light irradiation step of irradiating a light beam in accordance with drawing data of an upper layer pattern with respect to a drawing scheduled region of the substrate held on the stage;
The lower layer pattern formed in the planned drawing area of the substrate held on the stage is imaged by the imaging unit before the light beam is irradiated to the planned drawing area of the substrate held on the stage in the light irradiation step. An imaging process to
The position of the stage that moves while holding the substrate is detected as a first movement error in accordance with the imaging in the imaging process, and after the imaging in the imaging process until the light beam is irradiated in the light irradiation process A movement error detection step for detecting the position of the stage as a second movement error during
A control step of controlling drawing in the light irradiation step based on the drawing data of the upper layer pattern,
The control step includes
Based on the lower layer pattern included in the captured image acquired in the imaging step, a positional shift amount of the lower layer pattern in the captured image is acquired, and the first movement error is calculated from the positional shift amount of the lower layer pattern in the captured image. By calculating the amount of displacement of the lower layer pattern, which is the displacement of the lower layer pattern on the substrate,
By adding the second movement error to the position shift amount of the lower layer pattern on the substrate, the formation position of the upper layer pattern with respect to the lower layer pattern at the time of detection of the second movement error is calculated,
A drawing method comprising: controlling drawing in the light irradiation step based on a formation position of the upper layer pattern.   In the movement error detection step, the time required to calculate the formation position of the upper layer pattern in the control step and the time required to control drawing in the light irradiation step based on the formation position of the upper layer pattern are combined. The drawing method according to claim 6, wherein the second movement error is detected before the light beam is irradiated in the light irradiation step according to a predetermined time. The light irradiation step includes an irradiation position shift step of relatively shifting the optical path of the light beam in a direction orthogonal to a direction in which the stage travels,
The said control process controls drawing of the said upper layer pattern by shifting the optical path of the said light beam based on the formation position of the said upper layer pattern in the said irradiation position shift process. 8. The drawing method according to any one of items 7.   The control step includes the lower layer pattern of the substrate held on the stage by image processing using a lower layer pattern included in the captured image acquired in the imaging step and an image generated from design data of the lower layer pattern. The drawing method according to any one of claims 6 to 8, wherein the position of is calculated.   The drawing method according to claim 9, wherein the image processing in the control step is pattern matching processing.

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